Hearing loss is one of the most common conditions present at birth and can have long-lasting effects on a child’s ability to develop speech and language if left undetected. Research has shown that earlier identification of hearing loss significantly improves speech and language outcomes for these children.
- Types
Conductive Hearing Loss
This type of hearing loss is caused by a problem in the outer or middle ear. This means that sound is having difficulty traveling to the inner ear. Children with conductive hearing loss usually cannot hear faint sounds. Some causes of conductive hearing loss are fluid in the middle ear, wax in the ear canal or a hole in the eardrum. Most types of conductive hearing loss can be treated with medicine or surgery.
Sensorineural Hearing Loss
This type of hearing loss is caused by a problem in the inner ear. Children with sensorineural hearing loss may have difficulty hearing and understanding speech. Sensorineural hearing loss in young children can occur with certain infections before birth, from a lack of oxygen during birth or from genetic syndromes. Sensorineural hearing loss usually cannot be cured with medicine or surgery. While this type of hearing loss is permanent, most children will benefit from hearing aids and other hearing assistive technologies, along with speech, language and hearing therapies.
Mixed Hearing Loss
This type of hearing loss occurs when the child has both conductive and sensorineural hearing loss. For example a child with sensorineural hearing loss can also have middle ear problems (such as fluid in the middle ear).
Auditory Neuropathy Spectrum Disorder (ANSD)
Hearing loss that occurs when sound enters the ear normally, but because of damage to the inner ear or the hearing nerve, sound isn't organized in a way that the brain can understand. People with auditory neuropathy spectrum disorder may have normal hearing or hearing loss, and usually have trouble understanding speech.
- Degrees
The degree of hearing loss refers to how much hearing loss is present. There are six categories used to describe the degree of hearing loss. The numbers listed below represent the lowest intensity (or softest) sounds a person can hear.
Normal Hearing for a child (0 – 15 decibels, or dB)
Slight hearing loss (16 – 25 dB) A child with slight hearing loss may have trouble hearing faint (quiet) or distant speech. Children with slight hearing loss may benefit from hearing aids or other hearing assistive technologies, such as an FM system.
Mild hearing loss (26 – 40 dB)
For children with mild hearing loss, understanding speech can be difficult. They can usually hear well if they are listening to a single person speak in a quiet situation. However, they have more trouble hearing faint or distant speaking. Children with mild hearing loss usually can benefit from hearing aids and other hearing assistive technologies, such as an FM system.
Moderate hearing loss (41-55 dB)
Listening is a strain for children with moderate hearing loss. While they can understand what a person says if the person is close, it can be difficult for them to hear someone else in a noisy environment. Children with moderate hearing loss may miss 50 – 75% of speech in a conversation, and often need to have part of the conversation repeated. Children with moderate hearing loss usually can benefit from hearing aids and other hearing assistive technologies.
Moderately- severe hearing loss (56 – 70 dB)
Children with moderately-severe hearing loss can miss up to 100% of speech in a conversation and need for a conversation to be very loud. Again, children with moderately- severe hearing loss usually can benefit from hearing aids and other hearing assistive technologies.
Severe hearing loss (71 – 90 dB)
A child with severe hearing loss may hear a person speaking one foot away from his/her ear if the person speaks in a loud voice. They may be able to identify noises in their environment (such as traffic outside), but often appear to be ignoring conversation from the people around them.
Profound hearing loss (over 90 dB)
Children with profound hearing loss will not hear any speech. They may detect very loud sounds and are usually aware of vibrations (movements) around them. People with this degree of hearing loss may rely on vision (sight), rather than hearing, as their main way of communicating with other people. People with severe and profound hearing loss may benefit from technologies that amplify sound (make sounds louder), but may benefit more from a cochlear implant, or may use signing as a mode of communication.
- Risk Factors
Indiana Code for newborn hearing screening identifies four risk factors for delayed onset hearing loss that require reporting to the Indiana Department of Health. Babies who pass the newborn hearing screening but have one of the following risk factors need to be referred for further hearing testing between 9 and 12 months of age.
Family History of Congenital Childhood Hearing Loss
- Family members born with hearing loss in one or both ears
- A family member with a hearing loss that was identified in childhood
- Hearing loss not caused by a medical condition like ear infections
- Does not include family members with known causes of hearing loss like rubella, meningitis, loud noise exposure and/or trauma
Genetic Conditions with Hearing Loss
In-utero Infection (TORCH) for this pregnancy
- Toxoplasmosis - infected during or just before pregnancy, especially during first trimester
- Group Beta Strep (GBS) - sick infant with positive GBS culture
- Syphilis - infected during pregnancy, baby can be treated prior to delivery
- Rubella - infected primarily during the first trimester
- Cytomegalovirus (CMV) - can be transmitted through the placenta, birth canal or postnatally through breast milk
- Herpes Simplex Virus (HSV) -
- Yes if: Baby is diagnosed with neonatal herpes, Active infection during vaginal delivery Active infection during cesarean delivery with a premature membrane
- No if: Mother had a cesarean delivery with no membrane rupture, No active infection was present at birth
- Hyperbilirubinemia (Jaundice): At levels exceeding indication for exchange transfusion
Ear Malformations/Cranio-facial Anomalies
- Babies who cannot be screened at the hospital due to no ear, partial ear or no ear canal opening should be immediately referred to an audiologist (Level1) and to their physician (PCP)
- Babies who have one normal appearing ear should be screened in that ear
- Babies with craniofacial anomalies (including cleft lip and palate or any physical abnormality of the ear or surrounding area) who can be screened and pass should be referred for follow-up at 9-12 months of age
Other at-risk factors for hearing loss:
- Syndromes that are commonly associated with hearing loss (Down, Usher, Waardenburg and Neurofibromatosis Type 2)
- All infants with or without risk factors requiring neonatal intensive care for greater than 5 days, including any of the following: ECMO,* assisted ventilation, exposure to ototoxic medications (gentamycin and tobramycin) or loop diuretics (furosemide/lasix). In addition, regardless of length of stay: hyperbilirubinemia requiring exchange transfusion. (If uncertain about the risk, please check with the neonatologist)
- Any infant not passing two newborn hearing screenings
- Parental concern
Diagnostic Testing
Diagnostic Auditory Brainstem Response (also called the ABR)
During the Auditory Brainstem Response test, sounds are played into the baby’s ear at various loudness levels (measured in decibels, or dB) and pitches (also called frequencies). During the test, these sounds will be played through earphones placed directly into the baby’s ears. A bone oscillator (which vibrates, or moves, against the bone behind the ear or the forehead) will also be used during the ABR to determine what type of hearing loss a baby has.
Otoacoustic Emissions (also called OAE)
During the OAE test, sounds are played into the baby’s ear through a small earphone placed in the baby’s ear. A microphone measures an echo response from the inner ear. This information helps define the type of hearing loss. Diagnostic otoacoustic emissions are usually used with the ABR and other hearing test results.
Tympanometry
This test is used to determine how the eardrum and middle ear are working. During a tympanogram test, a small earphone is placed in the baby’s ear canal and air pressure is gently changed. This test is helpful in showing if there is an ear infection or fluid in the middle ear. This test is important because fluid or other problems in the middle ear can affect hearing
Air Conduction
During an air conduction test, sounds are played into the baby’s ears through earphones placed directly in the baby’s ear. This type of pure tone test gives you and the audiologist information about how all parts of your baby’s ear are working.
Bone Conduction
During a bone conduction test, sounds are produced by a bone oscillator, which is placed on the baby’s forehead. A bone conduction test will give you and the audiologist information about your baby’s sensorineural function (or how your baby’s inner ear is working).
